ABSTRACT
Beak and feather disease virus (BFDV) is the causative agent of a disease associated with feather dystrophy and beak deformity in psittacine birds named psittacine beak and feather disease (PBFD).1 The virus belongs to the genus Circovirus in the Circoviridae family that includes the smallest known viruses. All members of this genus share similar morphology and genome organization. Circoviruses are nonenveloped viruses with icosahedral nucleocapsids that contain a singlestranded circular DNA genome of about 2000 nucleotides.
